Submersible pump motor mounting



April 5, 1949. A. J. NELSON 2,466,324

v SUBMERSIBLE PUMP MOTOR MOUNTING 4 Filed Aug. 29, 1945 2 She'ets-Sheet 1 INVENTOR.

ARTHUR J. NELSON BYW A. J. NELSON April 5, 1949.

INVENTOR. ARTHUR J. NELSON Patented Apr. 5, 1949 UNITED STATES PATENT OFFICE 6 Claims.

electric motor and mounting of a submersible motor-pump unit made in accordance with my invention.

Fig. 2 is an enlarged cross section of Fig. 1 taken along the line 22 thereof.

Before describing the drawings in detail it will tend to a quicker understanding of them to state the present improved structure in the upper or electric motor portion only of an otherwise well-known direct driven motor centrifugal pump unit in which the motor is mounted on a vertically disposed shaft and the pump is also mounted on a vertically disposed shaft coaxial with the motor shaft and the motor is enclosed in an inverted cup or bell-like air filled housing bolted to the upper end of an extension of the pump casing, all to be submerged as a unit into the water to be pumped, ball float controlled means being provided for introducing air under pressure in the motor housing bell to maintain the desired Water level below it in the pump casing. One of the features of the present invention is to provide forced oil lubrication to the motor bearing or bell in which it operates.

As the present improvements and claims relate only to the motor mounting details, the lower part of the conventional pump casing, float valve air pressure control, and the pump, have been omitted in the drawings, as being well-known construction not involved in the present invention.

In the drawings the vertical pump shaft is designated I and extends downward in the extension 2 of the pump casing (through the upper pump bearing not shown to the pump runner not shown). The extension of the pump casing is here indicated as being cylindrical and provided at its upper end with a fixed outwardly projecting annular flange 3, preferably welded to the casing 2 as at 4, while removably secured to the upper side of flange 3 is a cylindrical housing 5 herein termed abell.

The bell 5 is closed at its upper end by a disk head 6 welded in place and preferably reinforced on top with cross ribs 1 provided with holes 8 to facilitate the use of hooks or devices for lowering or raising the unit from a well or other place to be pumped out. The lower part of the bell 5 is of greater diameter than the upper portion and is joined thereto by a shoulder or annular flange portion 9 as by Welding indicated, and which flange 9 is seated upon flange 3 of the pump casing and firmly secured thereto as by bolts Ill, a gasket 1 I being interposed to insure an air and watertight joint. The lower part 5 of the bell extends down well into the water adja cent the pump (not shown) and where it is left open so that the water rises up in it to a point below that shown in the drawing to thereby compress and confine air within the bell portion shown in the drawing.

Spaced within the upper portion 5 of the bell is another air and water-tight cylinder I2 also in the form of an inverted cup, closed on top by a head 13, and formed with or welded to an annular flange i 4 at its lower end also bolted to the upper flange or head 3 of the pump casing 2 and sealed thereagainst by the gasket H. As the cross section of the flange I4 is taken at a point where certain water piping or tubing i5, it pass vertically through it as well as through the flange 3 below it, the bolts which secure the flange l4 down against the head flange 3 are indicated just back of the pipes at 20.

This inner cylinder or cup 12 constitutes the outer supporting frame of the motor stator 2| and is removably secured thereto as by screws 22, while within the stator is the rotor 23 of the motor pressed on a tubular shaft 24 which surrounds the pump shaft l and is clear of contact therewith from the lower end of the tubular shaft all the way up to a point 25 above the rotor 23 and from which point upward the tubular shaft fits nicely upon shaft l and is secured thereto for driving the same as by a key or spline 25 and which also passes through an inverted cup or coupling nut 21 threaded as at 28 upon the solid shaft 5 which passes through the nut 2! and is formed with a squared wrench gripping lug l at its extreme upper end.

Coupling nut 21 is of increased internal diameter at its lower half and. internally threaded as at 29 and screws over external threads formed on the upper reduced end of the tubular shaft 24 to bear against a lock nut 30 also screwed over the tubular shaft 24 and which look nut seats upon the upper end of the inner ball race of a combined radial and thrust upper ball bearing assembly 3! to suspend both the pump at the lower end of shaft l as Well as the motor rotor 23 on its tubular shaft 24.

There is also a lower ball bearing 32 for the lower end of the tubular shaft, th mounting of which will be described later.

The upper ball bearing 3| is suspended in a housing 33 secured as by cap screws 34 to a cover plate 35 in turn secured as by cap screws 36 to the head l3 of inner cylinder |2. Cover plate 35 is formed with a central hand hole 31 closed by a cap 38 secured in place as by screws 39, it being understood that the cover 35 and cap 38 are made to fit air-tight either by good workmanship and/or by gaskets if required.

Suspended bearing housing 33 is of course stationary, and is formed with an inward shoulder 49 supporting the stationary outer race of the ball bearing 3|, while in contact with the lower end of the inner race of the ball bearing which is tight fitting on the tubular shaft, is a hollow cup member 4| which is supported on a shoulder 42 formed on the tubular shaft and threaded to the shaft as at 43 to draw it tightly against the shoulder.

Cup 4| rotates with tubular shaft 24 and is free of but entirely surrounds the bottom and sides of stationary housing 33 and is formed with a radially extending flange 44 close to the underside of cover plate 35, and also with a top bushing 45 projecting inwardly against housing 33 and rotatably fitting within a recess 46 in cover plate 35, while within the annular space between rotating cup 4| and fixed housing 33 is one or more oil wiping blocks or pads 41 secured to the housing and wiping against the inner upper end portion of revolving cup 4|.

Within fixed bearing housing 33 in contact with the outer ball race of bearing 3| is a cylindrical shell or oil spacer 54 provided with several small oil holes or grooves 6| through its lower end.

Housing 33 is also made hollow to provide an annular chamber 48 around the upper ball bear-.

ing 3| for cooling the same by water circulation as will later be described.

The lower ball bearing 32 may be lighter as indicated, as it carries no thrust load, and its inner or live ball race is supported on an inner shoulder 49 of a cup 59 to all intents and purposes the same as cup 4| described for the upper bearing. This cup is fitted upon the reduced diameter lower portion of the tubular shaft and secured thereto as by set screws and it embraces the lower fixed bearing housing 52 which is spaced within the cup 50 and fits nicely around the outer or stationary ball race of bearing 32. This housing is supended as by screws not shown from a laterally extending disk or spider 53 secured at its outer margin between flanges 3 and I4.

Extending upward from the outer ball race of ball bearing 32 is a tubular shell or oil spacer 55 to provide oil flow controlling holes 56 for the balls, and above the spacer 55 is an oil deflecting ring 57 secured to the tubular shaft as by the set screw indicated at 58. An oil wiper 59 secured to the housing 52 operating against the inner surface of cup 50, (as described for the upper bearing) is also provided. Housing 52 is also provided with an annular water circulating chamber 60 surrounding the lower ball bearing 32.

In cross section both the upper and lower bearing housings 33 and 52 and their outer cups 4| and 50 as well as oil shells 54 and 55 and oil apertures 6|, 56, and other details are both the same and therefore the showing of Fig. 2 being a transwise section through the upper bearing will clarify the construction of both.

In the enlarged cross section Fig. 2, the parts are numbered as described for the upper bearing mounting, but show the cage-like form of the housing member 33 as it appears in cross section, and the relation to it of the inner shell 54 and the small oil apertures 6|. The housing is formed with four relatively large depressions 33 or oil reservoir spaces in its outer wall just above the top of bearing 3| which open in smaller channels 33" to the oil shell 54, and which channels in turn are ported by small holes 6| at their lower ends (and which may be small grooves across the lower ends of the shell) so as to lead oil from the housing spaces back to the bearing to flow down through the ball races and outwardly at the bottom of the ball races through space 65 (see Fig. 1) and upwardly in the space 66 between housing 33 and cup 4| to rise as an annular mass of oil to overflow inwardly over certain outer walls 33 formed on housing 33 at the oil spaces 33' and flow downward and inward again through oil apertures 6| and over the bearing in continuous fiow during the operation of the motor, as will be more fully explained further on.

These four large oil spaces defined by the depressions 33" in the outer wall of fixed housing member 33 (see Fig. 2) form an upper oil reservoir entirely above the upper end of the ball bearing of a capacity to receive all of the oil drained from the bearing by the action of the revolving cup 4|, and from which upper reservoir the oil is metered by the fine channels 6| to properly lubricate the hearing at its upper end yet prevent resubmerging of the bearing until the motor is stopped. The bottom wall of this upper oil reservoir is the roof wall over the water circulating space 48, and is indicated by the surface shading in Fig. 2 of the drawing in the four largespaces defined by walls 33".

In Fig. 2 certain holes 61 and 68 are indicated as extending vertically in the housing member 33, and which are circulation water passages similarly numbered in Fig. 1 and respectively convey water to and from the bearing cooling chamber 48. The water being admitted to the upper end of passage 61 through a removable cylindrical screen 69 from the space 10 between cylinders 5 and I2, and which space is kept full of water, under pressure from a vertical stand pipe |5 extending upward from the pump through cylinder flanges 3 and I4 into water space 70. The water in this space also surrounds the motor and carries off any excess heat.

While it is presumed that the water forced up in pipe 15 has been screened, still it being a relatively long vertical pipe permits any heavy foreign matter to fall back and thereby cooperates with screen 69 which takes in water from the top of space TI], to insure clean water for circulating around the bearing water jacket or cooling chamber 48.

The outflowing water from the upper bearing water jacket passes upward through passage 68 and pipe 68 and out of pipe l6, downward through flanges M and 3, through an opening 12 in casing 2, thence upward through an opening 73 in plate 53 and downward as at l6 as the inlet pipe to the water jacket space 50 of the lower bearing 3|. The Water after circulating around the lower bearing is discharged through a tube 14.

Openings 12, '13, also additional openings 15 in casing 2 permit compressed air above the water level within cylindersZ and 5' to readily find its way into the motor chamber within inner cylinder l2, the compressed air being forced in from a suitable source through a pipe below under control of a float valve all as well-known and not shown in the drawing.

Electric energy for operating the motor is led in and out through asuitable waterproofed cable or cables 16 which passes down, and preferably through a pipe conduit not shown, into the water and out or by any other suitable means to avoid the escape of compressed air from the motor chamber.

Certain service plugs for filling and draining oil, cleaning, testing air tightness, etc., are provided where required, and some of which are indicated at 1118,19, and 8|.

The continuous flow of the oil over the bearings has been generally described, and as the bearings are initially filled with oil substantially to a level with the upper ends of the ball races, the motor starts with submerged or flooded ball bearings, but which condition quickly changes as the motor speeds up and the oil passes outward in the lower space 65 due to centrifugal force large- 1y from the effect of revolving outer cup 4i, and rises in annular space 66. However, when a quantity accumulates in the reservoir spaces above wall 33' and this wall being stationary the inner portion of this oil does not revolve but will slide downward over the remaining stationary surface of the housin 33 and upper end of the fixed outer ball race 3| to run back or inward and down between the bearin balls, this maintaining a constant circulation. The wipers or scrapers 41 and sealing rings provided on the outer or revolving bearing cup 4! prevent any upward traveling film of oil, the wipers being suitably formed to scrape the oil on the inner surface of the cup inward and downward.

Having thus described my improvements in a direct connected submersible vertical motorpump unit and the manner of its operation, what I claim is:

1. In a vertical electric motor mounting of the character described, a shaft on which the motor rotor is mounted and with the shaft extending above and below said rotor, a bearing embracing the upper end and a bearing embracing the lower end of said shaft, a motor casing surrounding said motor and supporting the stator of the motor, an air-tight closure removably secured over the upper end of said casing, housing means extending downwardly from said closure suspending the upper bearing and said shaft and its rotor on said bearing, an outer closed shell spacedly enclosing said motor casing to provide an outer water space therebetween for cooling the motor, means for introducing water under pressure to said outer water space, a water space formed around the upper bearing within said motor casing, and means circulating water from said outer water space around the upper bearing through its water space for cooling the same and out.

2. In a vertical electric motor mounting of the character described, a shaft on which the motor rotor is mounted and with the shaft extendin above and below said rotor, a bearing embracing the upper end and a bearing embracing the lower end of said shaft, a motor casing surrounding said motor and supporting the stator of the motor, an air-tight closure removably secured over the upper end of said casing, housing means extending downwardly from said closure suspending the upper bearing and said shaft and its rotor on said bearing, an outer closed shell spacedly enclosing said motor casing to provide a water space therebetween for cooling the motor,

means for introducing water under pressure to said water space, a water space formed around each bearing within said motor casing, means for supporting the lower bearing, and means circulating water from said water space around the upper bearing through its water space for cooling the same and thence around the lower bearing through its water space and out.

3. In a vertical electric motor mounting of the character described including a vertical hollow shaft on which the motor rotor is secured and supported in ball bearings one below and one above the motor and an inner work shaft passing through the hollow shaft in driving relation therewith; the improvements which comprise a motor casing surrounding the motor and provided with a covered hand hole at its upper end, bearing housing means extending downward from the upper end of said motor casing and formed to engage the lower end only of the nonrevolvin race of the upper ball bearing and hold it at fixed elevation, means for supporting both shafts and the motor rotor entirely upon the revolvable race of said upper ball bearing, whereby all the weight hangs thereon, and means for adjusting the longitudinal relation of both shafts.

i. In a vertical electric motor mounting of the character described, a vertical shaft on which the motor rotor is mounted, a ball bearing having an outer and inner ball race surrounding said shaft, housing means supporting the outer race stationary, a cup member secured to the shaft for revolving therewith and into which cup member said housin means depends, and oil passage spaces below and between said housing means and said cup member arranged to guide oil centrifugally displaced from said bearing outwardly and upwardly within said cup while revolving and inward over the stationary housing means back to the upper end of said bearing for recirculation therethrough as the shaft revolves and means above said bearing metering the oil returnin to the bearing, there being an oil reservoir above said bearing into which the ascending oil flows before being metered to said bearing and the means metering the oil comprising a cylindrical wall spaced outward from the shaft and defining the inner wall of said oil reservoir, and metering apertures extending through said wall.

5. In a vertical electric motor mounting of the character described, a vertical shaft on which the motor rotor is mounted, a ball bearing having an outer and inner ball race surrounding said shaft, housing means supporting the outer race stationary, a cup member secured to the shaft for revolving therewith and into which cup member said housing means depends, and oil passage spaces below and between said housing means and said cup member arranged to guide oil centrifugally displaced from said bearing outwardly and upwardly within said cup while revolvin and inward over the stationary housing means back to the upper end of said bearin for recirculation therethrough as the shaft revolves, fixed means supporting said housing means from its upper end, and an oil wiper mounted on said housing means operating against the inner wall of said cup to prevent excess climbing of the oil.

6. In a vertical shaft bearing assembly, a bearing comprising balls confined between an inner and outer race and with the inner race fitted around the shaft to revolve therewith, a cup member carried by the shaft surrounding said bearing and providing a lower oil reservoir for maintaining the bearing submerged, fixed means supporting the outer ball race stationary and providing an upper oil reservoir above the ball races and large enough'to hold substantially all the oil contained in the primary reservoir, said fixed means depending in said cup means, said cup member 'upon revolving with the shaft adapted to set up centrifugal forces to transfer substantially all the oil from the lower oil reservoir to the upper oil reservoir above the bearing races, said upper oil reservoir provided with meterin holes through its inner wall to allow oil to flow by gravity in restricted amount to lubricate the bearing balls below without submerging them.

- Y ARTHUR J. NELSON.

I REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

